21124759 has 2 divisors, whose sum is σ = 21124760. Its totient is φ = 21124758.

The previous prime is 21124711. The next prime is 21124769. The reversal of 21124759 is 95742112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21124759 - 2¹⁵ = 21091991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21124759.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21124709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562379 + 10562380.

It is an arithmetic number, because the mean of its divisors is an integer number (10562380).

Almost surely, 2^21124759 is an apocalyptic number.

21124759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124759 is an equidigital number, since it uses as much as digits as its factorization.

21124759 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 21124759 is about 4596.1678602941. The cubic root of 21124759 is about 276.4376894494.

The spelling of 21124759 in words is "twenty-one million, one hundred twenty-four thousand, seven hundred fifty-nine".